Background

Sewer pipe lining

Cured-in-place pipe (CIPP) lining is a way to fix underground pipelines without digging. Work crews access the pipe through an existing maintenance hole and insert a flexible liner inside. The liner is then inflated with hot water or steam to cure it. As a result, the liner hardens to form a rigid, smooth surface that seals any cracks in the pipe. This extends the service life of the pipe, decreases ongoing maintenance costs, and reduces construction impacts, which lowers the impact to the environment.

What to expect during a pipe lining project

These impacts are specific to pipe lining projects. Please see below for impacts during open trench repair.

Chemical odor There will be some steam and odor during the sewer lining process. The odor comes from a chemical called "styrene" which is in the pipe liner. The steam and odor should dissipate quickly once the lining process is complete.

More information about Styrene

If you experience odor in your home, take the following steps the morning of construction to reduce the smell:

Close windows and doors that face the construction work

Cover floor drains with a wet towel or a plastic bag filled with water

Run water in sinks or tubs and flush toilets that you do not use often to make sure your P-traps are full

P-traps are U-shaped sections of pipe that hold water to prevent sewer gas from enter your house or building. View an illustration of a P-trap(pdf)

Limit the use of toilets and sinks

Parking impacts There will be reduced parking because of trucks and equipment at either end of the sewer pipe. Parking impacts during the lining process usually happen in one day, from 6 a.m. to 7 p.m. The contractor will typically place “No Parking” signs at least 48 hours in advance.

Reduced parking ensures that the contractor has adequate room to work around the maintenance holes, has room for equipment, and that no privately-owned vehicles are damaged during construction.

Liner installation Lining the sewer pipe should take one day to complete. Repair crews typically work from 6 a.m. to 7 p.m.

While the pipe is being lined, all sewer connections will be temporarily out of service. Limiting sewer use during this time helps prevent sewer backups and damage to the new liner. If you received a notice from the contractor about limiting your sewer usage:

Do not take showers or baths

Do not wash clothes or dishes

Turn off any sump pumps connected to the sewer service

Limit the use of toilets and sinks

The steam and odor should dissipate quickly once the lining process is complete.

Open trench sewer repair

Many sewer pipes need to be repaired by digging down to, and exposing the pipe, to work on it. The contractors will repair or replace segments of the pipe, refill the trench with sand or gravel, and then repave over the trench. These sewer system repairs are needed to provide service to homes and businesses.

Impacts during an open trench sewer repair

Unless otherwise notified, homes and businesses can continue to use their normal sewer services while the pipe segments are being repaired. However, you can expect:

Ground surface trench digging and restoration

Reduced street parking for the duration of the work

The contractor will typically place “No Parking” signs at least 48 hours in advance

City-Wide Information

Top Requests

Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility. The Water Utility provides more than 1.3 million customers in King County with a reliable water supply; the Drainage and Wastewater Utility collects and disposes of sewage and storm water; and the Solid Waste Utility collects and disposes of recycling, yard waste, and residential and commercial garbage. All three utilities strive to operate in a cost-effective, innovative and environmentally responsible manner. SPU also houses the Engineering Services line of business, which serves both City departments and outside agencies, providing efficient, customer-oriented engineering services that assist clients with replacing, improving, and expanding facilities with the least possible disruption to the community.